🕊️ unenv

<!-- automd:badges color=yellow packagephobia -->

<!-- /automd -->

[!NOTE] You are on the development (v2) branch. Check out v1 for the current release.

unenv provides polyfills to add Node.js compatibility for any JavaScript runtime, including browsers and edge workers.

🌟 Used by

• Nitro
• Nuxt
• Cloudflare
• ESM.sh

Usage

The defineEnv utility can generate a target environment configuration.

import { defineEnv } from "unenv";

const { env } = defineEnv({
  nodeCompat: true,
  npmShims: true,
  resolve: true,
  overrides: {},
  presets: [],
});

const { alias, inject, external, polyfill } = env;

You can then integrate the env object with your build tool:

<details>

| Bundler | alias | inject | external | | -------- | ----------------------------------------------------------------------------- | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------ | | rollup | @rollup/plugin-alias | @rollup/plugin-inject | external | | rolldown | resolve.alias | inject | external | | vite | resolve.alias | @rollup/plugin-inject | ssr.external | | esbuild | alias | inject | external | | rspack | resolve.alias | - | externals | | webpack | resolve.alias | webpack-plugin-inject | externals |

</details>

Options

• nodeCompat: (default: true)
  • Add alias entries for Node.js builtins as <id> and node:<id>.
  • Add inject entries for Node.js globals global, Buffer, and process.
• npmShims: (default: false)
  • Add alias entries to replace npm packages like node-fetch with lighter shims.
• resolve: (default: false) Resolve config values to absolute paths.
• overrides: Additional overrides for env config.
• presets: Additional presets (for example @cloudflare/unenv-preset).

unenv/ polyfills

You can also directly import unenv/ polyfills:

| Polyfills | Description | Source | | ------------------ | ---------------------------------- | -------------------------------------------------------------------------------------- | | unenv/mock/* | Mocking utils | src/runtime/mock | | unenv/node/* | APIs compatible with Node.js API | src/runtime/node | | unenv/npm/* | NPM package shims | src/runtime/npm | | unenv/polyfill/* | Global polyfills | src/runtime/polyfill | | unenv/web/* | Subset of Web APIs | src/runtime/web |

Node.js compatibility

unenv replaces Node.js built-in modules compatible with any runtime (view source).

<details> <!-- automd:file src="./coverage/unenv.md" -->

• ✅ node:assert
• ✅ node:assert/strict
• ✅ node:async_hooks
• ✅ node:buffer
• ✅ node:child_process
• ✅ node:cluster
• ✅ node:console
• ✅ node:constants
• ✅ node:crypto
• ✅ node:dgram
• ✅ node:diagnostics_channel
• ✅ node:dns
• ✅ node:dns/promises
• ✅ node:domain
• ✅ node:events
• ✅ node:fs
• ✅ node:fs/promises
• ✅ node:http
• ✅ node:http2
• ✅ node:https
• ✅ node:inspector
• ✅ node:inspector/promises
• ✅ node:module
• ✅ node:net
• ✅ node:os
• ✅ node:path
• ✅ node:path/posix
• ✅ node:path/win32
• ✅ node:perf_hooks
• ✅ node:process
• ✅ node:punycode
• ✅ node:querystring
• ✅ node:readline
• ✅ node:readline/promises
• ✅ node:repl
• ✅ node:stream
• ✅ node:stream/consumers
• ✅ node:stream/promises
• ✅ node:stream/web
• ✅ node:string_decoder
• ✅ node:sys
• ✅ node:timers
• ✅ node:timers/promises
• ✅ node:tls
• ✅ node:trace_events
• ✅ node:tty
• ✅ node:url
• ✅ node:util
• ✅ node:util/types
• ✅ node:v8
• ✅ node:vm
• ✅ node:wasi
• ✅ node:worker_threads
• ✅ node:zlib

<!-- /automd --> </details>

Manual mocking

<details>

// Magic proxy to replace any unknown API
import MockProxy from "unenv/mock/proxy";

// You can also create named mocks
const lib = MockProxy.__createMock__("lib", {
  /* overrides */
});

</details>

(view source)

Nightly release channel

You can use the nightly release channel to try the latest changes in the main branch via unenv-nightly.

<details>

If directly using unenv in your project:

{
  "devDependencies": {
    "unenv": "npm:unenv-nightly"
  }
}

If using unenv via another tool (Nuxt or Nitro) in your project:

{
  "resolutions": {
    "unenv": "npm:unenv-nightly"
  }
}

</details>

License

<!-- automd:contributors license=MIT author=pi0 -->

Published under the MIT license. Made by @pi0 and community 💛 <br><br> <a href="https://github.com/unjs/unenv/graphs/contributors"> <img src="https://contrib.rocks/image?repo=unjs/unenv" /> </a>

<!-- /automd --> <!-- automd:with-automd -->

---

🤖 auto updated with automd

<!-- /automd -->